[apps] Don't forget to call viewWillAppear

At the moment ViewController::viewWillAppear doesn't do anything, so
there is no real impact. But if we want to use it it needs to be called
from subclasses.

apps/graph/graph/calculation_parameter_controller.cpp

@@ -33,6 +33,7 @@ View * CalculationParameterController::view() {
 }
 
 void CalculationParameterController::viewWillAppear() {
+  ViewController::viewWillAppear();
   m_selectableTableView.reloadData();
 }